Cassini prepares for dramatic climax to its mission
NASA's Cassinispacecraft recently completed the second of five planned burnsdesigned to maneuver the spacecraft out of Saturn's ring plane, andinto a polar orbit. The move is being made in preparation for thefinal phase of Cassini's mission, which will see the spacecraftperform a series of daring orbits, maximizing the probe's scientificoutput prior to the mission's termination.
The venerated probe hadbeen operating in Saturn's equatorial orbit since insertion there inSpring 2014, making use of the ring plane to undertake a series offinal encounters with the gas giant's eclectic moons.
These close passes haveprovided scientists at NASA with a wealth of new informationregarding the nature of the Saturnian system, but unfortunately,Cassini's operational life is coming to an end, and so missionoperators are setting the probe on a new, polar orbit.
The recent maneuver that took place on Jan. 23 was the second in a series of fiveplanned burns, which will harness the gravitational force exuded byTitan to manipulate Cassini's orbital trajectory. At 5:47 p.m. ESTon the 23rd, Cassini's main hydrazine engine fired up fora 35-second burst, altering the probe's velocity by 22.3 ft per sec(6.8 m per sec).
The encounter withTitan, which is due to take place on Feb. 1, will have a far greaterimpact on the spacecraft, altering its velocity by 2,539 ft per sec(774 m per sec). The next transfer burn is scheduled to take place onMar. 25, setting up another Titan gravity assist on Apr. 4.
The intricate dancebetween Cassini and Titan is acting as a crescendo leading up to thespacecraft's final act. Once inserted in its polar orbit, Cassiniwill fly high above Saturn, just beyond the gas giant's F-ring.
The probe will complete20 of these orbits, before altering its trajectory once more toplunge between the innermost ring and the planet's surface 22 times,before ending its mission by hurtling into Saturn's dense atmosphereon Sep. 15, 2017.